The newly polished messaging, tailored to rebut Republican and Democratic attacks separately, was to be supported by new campaign commercials showing employees of companies started and rescued by private-equity firm Bain Capital LLC, Romney's former company, telling stories of gratitude, campaign advisers said.

The new positioning showing Romney as a champion of capitalism, will highlight "our identification with core Republican principles," an unidentified senior Romney adviser told Politico as the campaign of GOP presidential hopefuls focused on wooing conservative South Carolina voters ahead of the state's Jan. 21 primary.

Romney told reporters aboard his campaign plane flying to South Carolina from New Hampshire Wednesday the repositioning would include distinguishing him from his opponents, whose backgrounds are largely limited to politics.

"The other guys, they don't have a record in the private economy, so it'll be a different, I think, approach," he said.

At the same time, House Speaker Newt Gingrich of Georgia, Texas Gov. Rick Perry and their supporters insisted they would keep up attacks on Romney, while Rep. Ron Paul of Texas, former Utah Gov. Jon Huntsman Jr. and former Sen. Rick Santorum of Pennsylvania said they would stop criticizing his Bain tenure.

Gingrich, one of the harshest critics of Romney's Bain years, acknowledged Wednesday it was a tough argument, but his campaign and outside supporters said they had no plans to stop.

"We're not going to back off an inch," Rick Tyler, a senior adviser to pro-Gingrich "super PAC" Winning the Future was quoted in The New York Times as saying.

The political action committee introduced a scathing 28-minute video about Romney's work at Bain, featuring interviews with distraught people who say they lost their jobs at companies taken over by the venture capital group. The PAC said it planned to spend as much as $3.4 million on ads attacking Romney in South Carolina, many of them based on footage from the video.

Perry described Romney as a "vulture capitalist," while spotlighting factories in South Carolina where he said Bain had cut jobs during Romney's tenure.

"I understand restructuring ... but the idea that we can't criticize someone for these get-rich-quick schemes is not appropriate from my perspective," Romney told voters at a restaurant rally in Lexington, S.C.

By contrast, Paul and Huntsman told an audience of mostly students in the state capital, Columbia, Wednesday bashing Bain was a mistake. Huntsman told reporters he believed Romney should be judged on his gubernatorial record, not his Bain record.

Santorum urged a tactics change too.

"It's this hostile rhetoric that unfortunately ... some in our party now, even some running for president, will engage in with respect to capitalism," he told a crowd in West Columbia Wednesday night.

"It is bad enough for Barack Obama to blame folks in business for causing problems in this country. It's one other thing for Republicans to join him," he said.

Bain specialized in buying up companies with the idea of turning them around and then selling them at a profit. The firm's record includes some successes, and Romney claims it helped create 100,000 jobs, although his campaign has declined to provide specifics on how it arrived at that number.

Bain often cut jobs to make its companies profitable.

In non-Romney-focused campaigning, Santorum told a Christian radio station he had home-schooled his children -- a practice embraced by some evangelical Christians who wish to teach a "Christian curriculum." He said he supported anti-abortion legislation and called for "all conservatives to unite."

Paul's campaign broadcast an ad attacking Santorum for "a record of betrayal" on federal spending.

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